Some consumer and commercial electronic devices implement single channel acoustic noise reduction (SCANR) to reduce noise (e.g., environmental noise) from a single stream of audio signal. These devices use various types of spectral subtraction techniques to reduce the noise in the audio signal. The spectral subtraction techniques are somewhat suitable for only stationary noise or very slow varying noise. However, in real time user environments, the noise is not stationary and may vary significantly over a period of time.